New testcase

[Richard Biener]

The following adds a testcase I managed to break when trying to make
SSA names safe_from_p.

Richard.

2019-03-27  Richard Biener  <rguent...@suse.de>

        * gcc.dg/torture/20190327-1.c: New testcase.

Index: gcc/testsuite/gcc.dg/torture/20190327-1.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/20190327-1.c   (nonexistent)
+++ gcc/testsuite/gcc.dg/torture/20190327-1.c   (working copy)
@@ -0,0 +1,18 @@
+/* { dg-do run } */
+
+typedef long v2di __attribute__((vector_size(16)));
+v2di v;
+void __attribute__((noinline))
+foo()
+{
+  v = (v2di){v[1], v[0]};
+}
+
+int main()
+{
+  v[0] = 1;
+  foo ();
+  if (v[0] != 0 || v[1] != 1)
+    __builtin_abort ();
+  return 0;
+}